The reflexive personnal pronoun "lui" you use to qualify the restaurant isn't correct.
A restaurant is a thing (not alive): you should use the composed form of masculine singular demonstrative pronoun : "celui-ci" or "celui-là".

You can only use the preposition "que" in the first sentence and "de" in the second while keeping the same meaning.
If you use "de", the sentence could become for example: "D'habitude, je mange dans un autre restaurant de Paris."